This invention relates generally to openable protective covers for prepacked foods, and more specifically it relates to a protective tab for an opening device provided in a protective lid used in connection with an extendable spun aluminum foil covering a pan containing prepacked popcorn. The protective covers of this type have been described in detail in the above-mentioned related patent applications. Generally, such prior-art covers include a circular cardboard lid covering the extendable spun aluminum foil which in turn covers the popcorn pan. An opening device formed in the lid includes circular score lines provided on both sides of the lid at a certain distance from the edge and an additional score with star-shaped angular through-cuts. The user before heating the pan first removes the major central part of the lid by bending the angular through-cuts to form a pulling tab which is grasped by fingers and tears-open the lid along the score lines. The ring-shaped narrow border portion of the lid remains attached to the edge of the pan while the large central area of the spun aluminum foil which during heating will expand, is exposed.
In order to protect the extendable spun aluminum covering against puncturing during the opening process, the angular pulling tab is backed by a foldable protective tab which is formed by stamping simultaneously with the cardboard lid and forms a satellite tab. Conventionally, this protective satellite tab has a substantially circular configuration whereby its top portion is cut away so as to form a semi-elliptical cutout and its base portion is integral with the circumference of the larger protective lid proper. Normally, this integral connection line is scored by interrupted cuts coinciding with the perimeter of the larger lid. Conventionally, the length of this base is about 1 5/16 of an inch. In addition, the satellite tab is provided with two semi-elliptical rows of cuts which upon folding the tab below the lid coincide with the two scored circles of the opening device in the lid.
The size and shape of the protective tab is such that when the tab is folded underneath the circular large lid it backs the angular cuts of the opening device thereby preventing the accidental puncturing of the spun aluminum foil covering the popcorn itself when the user bends the corners of the pulling tab by a knife, for example. When the internal part of the lid is removed by the opening device, the protective tab remains over the expandable aluminum foil and when the pan is subject to the heating-up process which activates the expansion of the spun aluminum covering, the protective tab rises together with the aluminum foil due to the pressure exerted by the heated vapors inside the pan. Experience has shown, however, that at some point the tab resists further expansion of the spun aluminum and is thus prone to puncture the foil bag thereby interfering with completion of the cooking cycle of the popcorn.